The development of real-time systems is based on a variety of different methods and notations. Despite the purported benefits of formal methods, informal techniques still play a predominant role in current industrial practice. Formal and informal methods have been combined in various ways to smoothly introduce formal methods in industrial practice. The combination of real-time structured analysis (SA-RT) with Petri nets is among the most popular approaches, but has been applied only to requirements specifications. This paper extends SA-RT to specifications of the detailed design of embedded real-time systems, and combines the proposed notation with Petri nets.

Currently, mobile technology is undergoing a high growth stage, allowing an increasing plethora of mobile devices (handheld PCs, handsets, etc.) to daily access to distributed resources and information. This availability entails the requirement for transactional capabilities adapted to the specific characteristics of the mobile environment without losing the consistency and reliability guarantees of traditional OLTP systems. This paper surveys the definition and extension of transactional models to a mobile environment, starting with an explanation of this environment and a review of transactional systems applied to mobile computing. Afterwards, a framework for analyzing competing mobile models is defined. This framework allows for different constraints to be imposed to the most general "motion independence" requirement. Finally, existing mobile transaction proposals are assessed against the framework and classified, highlighting their relative strengths and weaknesses in different situations.

We emphasize the importance of formal executable specifications in the development of real-time systems, as a means to assess the adequacy of the requirements before a costly development process takes place. TRIO is a first-order temporal logic language for executable specification of real-time systems that deals with time in a quantitative way by providing a metric to indicate distance in time between events and length of time intervals. We summarize the language and its model-parametric semantics. Then we present an algorithm to perform history checking, i.e., to check that a history of the system satisfies the specification. This algorithm can be used as a basis for an effective specification testing tool. The algorithm is described; an estimation of its complexity is provided; and the main functionalities of the tool are presented, together with sample test cases. Finally, we draw conclusions and indicate directions of future research.

Addresses the problem of formally analyzing the properties of real-time systems. We propose a method based on modeling the system as a timed Petri net and on specifying its properties in TRIO, an extension of temporal logic suitable for dealing explicitly with time and for measuring it. Timed Petri nets are axiomatized in terms of TRIO, so that their properties can be derived as theorems in the same spirit as the classical Hoare method allows one to prove properties of programs coded in a Pascal-like language. The method is also illustrated through an example.>

We describe how formal specifications given in terms of a high-level timed Petri net formalism (TB nets) can be analyzed to check the temporal properties of bounded invariance (the systems stays in a given state until time τ) and bounded response (the system will enter a given state within time τ). In particular, we concentrate on specifications given in a hierarchical, top-down manner, where one specification level refines a more abstract level.

We emphasize the importance of formal executable specifications in the development of real-time systems, as a means to assess the adequacy of the requirements before a costly development process takes place.TRIO is a first order temporal logic language for executable specification of real-time systems that deals with time in a quantitative way by providing a metric to indicate distance in time between events and length of time intervals.We summarise the language, its straightforward model-theoretic semantics, and a tableaux-based algorithm to decide satisfiability.Then we present an efficient algorithm to perform history-checking, i.e., to check that a history of the system satisfies the specification.This algorithm can be used as a basis for an effective specification testing tool.The algorithm is described, a qualitative estimation of its complexity is provided, and the main functionalities of the tool are presented, together with sample test cases.Finally, we draw the conclusions and indicate directions of future research.